The Structure And Function Of The Heart Flashcards
What is cardiac output?
Cardiac output is the volume of blood pumped through each ventricle per minute
How do you calculate cardiac output?
Cardiac Output = Heart Rate x Stroke Volume
Do the left and right ventricles pump the same amount of blood through the aorta and pulmonary artery?
Yes
What is diastole?
During diastole, blood returning to the atria flows into the ventricles.
What is atrial systole?
Atrial systole transfers the remainder of the blood through the atrio ventricular (AV) valve
What is ventricular systole?
Ventricular systole closes the AV valves and pumps the blood through the semi lunar (SL) valves to the aorta and pulmonary artery
What happens in the diastole after ventricular systole?
The higher pressure in the arteries closes the SL valves and the process repeats.
What causes heart sounds?
The opening and closing of the Atrio Ventricular and Semi Lunar valves are responsible for the heart sounds
What is used to check for heart beats?
A stethoscope
Where does the heartbeat originate?
In the heart itself
What sets the rate at which the heart contracts
auto-rhythmic cells of the sino-atrial node ( pacemaker ), located in the wall of the right atrium, sets the rate at which the heart contracts
What times the cardiac muscle cell contraction?
Impulses from the sino atrial node that are generated, spreading through the atria causing atrial systole.
Where do impulses from the sino atrial node travel to cause ventricular systole?
The impulses travel to the atrio-ventricular node, located in the centre of the heart, these impulses then travel down fibres in the central wall of the heart and then up through the walls of the ventricles, causing ventricular systole
What do impulses in the heart generate?
Currents that can be detected by an electrocardiogram (ECG)
What is the function of the medulla on the cardiovascular system?
The medulla regulates the sino atrial node through the antagonistic action of the autonomic nervous system
